Reductant refill and purging system

Abstract

A system for refilling a reductant tank of a first machine is provided. The system includes a reductant reservoir, a first valve, and a pump. The first valve is fluidly connected to the reductant reservoir. The pump is fluidly connected to the first valve. Further, a nozzle is fluidly connected to the first valve. The first valve provides a reductant flow from the reductant reservoir to the pump, and from the pump to the nozzle when in a first position, and reverses the reductant flow from the nozzle to the pump, and from the pump to the reductant reservoir in a second position. Also, a pilot line is selectively associated with an outlet of the pump and the first valve. When pressure between the pump and the nozzle exceeds a threshold, pilot pressure causes the first valve to shift from the first position to the second position.

What is claimed is: 
     
       1. A system for refilling a reductant tank of a first machine, the system comprising:
 a reductant reservoir; 
 a first valve fluidly connected to the reductant reservoir; 
 a pump fluidly connected to the first valve; 
 a nozzle fluidly connected to the first valve, wherein the first valve provides a reductant flow from the reductant reservoir to the pump, and from the pump to the nozzle when in a first position, and reverses the reductant flow from the nozzle to the pump, and from the pump to the reductant reservoir in a second position; and 
 a pilot line selectively associated with an outlet of the pump and the first valve, wherein when pressure between the pump and the nozzle exceeds a threshold, pilot pressure causes the first valve to shift from the first position to the second position. 
 
     
     
       2. The system of  claim 1  further including a fluid line between the nozzle and the reductant reservoir, the nozzle having a first position that allows the reductant flow through the nozzle to or from the pump, and a second position that provides a fluid connection from the fluid line to the first valve in the second position to the pump. 
     
     
       3. The system of  claim 1  further including a second valve disposed within the pilot line fluidly connected to the nozzle, the second valve having a first position that isolates the pilot line from the nozzle and a second position that allows the reductant to flow from the pilot line through the nozzle to the pump, causing the first valve to shift from the second position to the first position. 
     
     
       4. The system of  claim 1 , wherein the reductant tank is located on-board the first machine, the reductant tank further including a level control valve, wherein the level control valve is configured to shut-off and create a back-pressure in the system through the nozzle and the first valve in the first position to the pump based on a filled condition of the reductant tank. 
     
     
       5. The system of  claim 4  further including an air inlet valve located in the reductant tank, wherein the air inlet valve is configured to introduce air into the system when the first valve is in the second position. 
     
     
       6. The system of  claim 2 , wherein the nozzle is manually moved from the first position to the second position. 
     
     
       7. The system of  claim 1  further including a check valve disposed in the pilot line associated with the outlet of the pump, the first check valve configured to prevent reverse flow of the reductant towards the pump. 
     
     
       8. The system of  claim 1  further including an accumulator provided in the pilot line. 
     
     
       9. The system of  claim 2  further including a check valve in the fluid line, the second check valve configured to prevent the reductant flow towards the reductant reservoir. 
     
     
       10. The system of  claim 1  further including a sight gauge to check the reductant flow from the pump. 
     
     
       11. A method for refilling a reductant tank of a first machine, the method comprising:
 providing a reductant reservoir; 
 providing a first valve fluidly connected to the reductant reservoir; 
 providing a pump fluidly connected to the first valve; 
 providing a nozzle fluidly connected to the first valve, wherein the first valve provides a reductant flow from the reductant reservoir to the pump, and from the pump to the nozzle when in a first position, and reverses the reductant flow from the nozzle to the pump, and from the pump to the reductant reservoir in a second position; and 
 providing a pilot line selectively associated with an outlet of the pump and the first valve, wherein when pressure between the pump and the nozzle exceeds a threshold, pilot pressure causes the first valve to shift from the first position to the second position. 
 
     
     
       12. The method of  claim 11  further including providing a fluid line between the nozzle and the reductant reservoir, the nozzle having a first position that allows the reductant flow through the nozzle to or from the pump and a second position that provides a fluid connection from the fluid line to the first valve in the second position to the pump. 
     
     
       13. The method of  claim 11  further including providing a second valve in the pilot line fluidly connected to the nozzle, the second valve having a first position that isolates the pilot line from the nozzle and a second position that allows the reductant to flow from the pilot line through the nozzle to the pump, causing the first valve to shift from the second position to the first position. 
     
     
       14. The method of  claim 11  further including introducing air into the system when the first valve is in the second position via an air inlet valve provided in the reductant tank. 
     
     
       15. The method of  claim 12  further including manually shifting the nozzle from the first position to the second position. 
     
     
       16. A refill and purge system comprising:
 a first machine including:
 a reductant tank located on-board the first machine; and 
 a receiver fluidly connected to the reductant tank; and 
 
 a second machine removably connected to the first machine via a refill line, the second machine including:
 a reductant reservoir; 
 a first valve fluidly connected to the reductant reservoir; 
 a pump fluidly connected to the first valve; 
 a nozzle located at one end of the refill line, the nozzle configured to connect with the receiver, wherein the nozzle is fluidly connected to the first valve, and wherein the first valve provides a reductant flow from the reductant reservoir to the pump, and from the pump to the refill line and the nozzle when in a first position, and reverses the reductant flow from the nozzle to the pump, and from the pump to the reductant reservoir in a second position; and 
 a pilot line selectively associated with an outlet of the pump and the first valve, wherein when pressure between the pump and the nozzle exceeds a threshold, pilot pressure causes the first valve to shift from the first position to the second position. 
 
 
     
     
       17. The refill and purge system of  claim 16  further including a fluid line between the nozzle and the reductant reservoir, the nozzle having a first position that allows the reductant flow through the nozzle to or from the pump, and a second position that provides a fluid connection from the fluid line to the first valve in the second position to the pump. 
     
     
       18. The refill and purge system of  claim 16  further including a second valve disposed within the pilot line fluidly connected to the nozzle, the second valve having a first position that isolates the pilot line from the nozzle and a second position that allows the reductant to flow from the pilot line through the nozzle to the pump, causing the first valve to shift from the second position to the first position. 
     
     
       19. The refill and purge system of  claim 16 , wherein the reductant tank further includes a level control valve, the level control valve configured to shut-off and create a back-pressure in the refill and purge system through the nozzle and the first valve in the first position to the pump based on a filled condition of the reductant tank. 
     
     
       20. The refill and purge system of  claim 17 , wherein the nozzle is manually moved from the first position to the second position.